There are many operations in agriculture and industry that require the dispensing of measured quantities of dry material. For Example, in modern dairy farming and the like, it is recognized that individual animals of a herd often require special diets and dietary supplements and that it is not feasible to feed the herd en masse, with each animal determining its own intake. Some efforts are being made to supply individual animals with approximate food quantities. However, it is highly desirable to monitor the animals feed very closely and to maintain a close surveillance so that results can be determined and evaluated.